Johnson’s tests equipment performance in providing air delivery rates needed to achieve the highest potential performance and efficiency.
Simple Static Pressure Tests are used to determine the resistance to airflow that a given duct system exerts upon the indoor fan.
The supply and return air ducts are tested individually and collectively to determine if the duct system is adequate for the equipment used.
Technicians can determine if airflow problems relate to the supply air ducts, the return air ducts or a combination of both.
The data gathered is used to assess whether improvements are needed, and if so what improvements would yield the greatest gains in performance and efficiency.
Sometimes the total volume of conditioned air being delivered by the equipment is adequate but the distribution is not even between rooms. Test and balance procedures are used to measure the CFM ( cubic-feet-per-minute ) delivered to each room in order to confirm that the distribution is even among all spaces served by the system.
Technicians use a “Flow Hood” to measure the volume of air coming out of each supply air diffuser. They add these amounts to calculate the total volume of air supplied to the entire space served. Dividing the total available airflow by the amounts delivered to each room reveals the percentage of total capacity being delivered to each individual space.
The results of these measurements are used to make adjustments to volume dampers and regulate the flow rates to individual rooms to achieve a more even distribution. After changes have been made, the measurements are taken again to confirm improvements and the equipment static pressure is measured again to verify that changes are in keeping with equipment tolerances.